1. Field of the Invention
The present invention relates to an image forming apparatus, such as a projector, that uses light sources for plural colors including red (R), green (G), and blue (B).
2. Background Art
A display, such as a projector that projects an image onto a screen, has been known. The main stream has been a type using a high pressure mercury-vapor lamp as the light source. However, a laser display using a laser as the light source is being studied in recent years. Using red (R), green (G), and blue (B) lasers as the light sources is advantageous in many respects, for example, a color reproducible range is broadened markedly to the extent that color representation close to original colors is enabled and low power consumption can be achieved.
Of the needs for a projector, one need is to reduce the projector to a portable size so as to be carried around. In addition, in a case where lasers are used as the light sources, speckle noises, which give a problem in image quality, are known to occur. To satisfy the needs and eliminate the problems as above, proposals have been made, for example, in JP-A-2005-99160 and JP-A-11-64789.
However, JP-A-2005-99160 achieves a reduction of the apparatus size by making the lasers compact on one hand, but it has a problem that the cost is increased on the other. Further, because JP-A-11-64789 removes the speckle noises by providing the configuration to remove speckle noises separately for each of the R, G, and B light sources, it has a problem that the apparatus size is undesirably increased.